1. Field
Example embodiments relate generally to a display device. More particularly, embodiments relate to a metal wire, a thin-film transistor substrate, and a method for manufacturing a thin-film transistor substrate.
2. Description of the Related Art
Generally, flat or curved panel displays (e.g., Liquid Crystal Displays or LCD's) include a display substrate having patterned wirings integrally formed for interconnecting circuitry such as thin-film transistors (“TFT's”), which are used as switching elements for driving corresponding pixel units of the display device. More specifically, so-called gate lines and data lines may be provided in different metal wiring layers as signal lines connected to respective TFTs for controlling charging and discharging of corresponding pixel electrodes. Yet more specifically, the gate lines are configured for transmitting corresponding gate driving signals and the data lines are configured for transmitting corresponding source driving signals for respective gate and source terminals of respective TFT's.
As the display area size of display apparatuses increase, and as customer's demand for display apparatuses having higher resolutions grow, the length of the gate lines and of the data lines increase, while at the same time the width of the gate and data lines tend to decrease, and as a result electric resistance, as seen from a signal providing source point to a TFT located at a far end of a gate or data line, undesirably increase. Copper (Cu) is a metal having relatively a low resistance, and thus a metal wire including copper has excellent electric conductivity. Furthermore, copper is relatively abundant as a natural resource. However, when the metal wires included in the display device are formed of copper as a single layer structure, adhesive strength between the substrate and the metal wires is low and the metal wires may be corroded by moisture. In addition, when the metal wires are formed of titanium-copper alloy, the substrate can be damaged because the metal wires are etched using an etchant that includes fluorine (F).